London , England -LRB- CNN -RRB- -- British Prime Minister Gordon Brown is denying allegations of `` abusive behavior '' and `` volcanic eruptions of foul temper '' ahead of the publication of a new book by a top British political journalist .

The claims come in a book by Andrew Rawnsley of the Observer newspaper , which will be released March 1 . The newspaper began running excerpts on Sunday .

`` These malicious allegations are totally without foundation , '' Brown 's official spokesman said in a statement Saturday . The spokesman is traditionally not quoted by name .

The Observer claimed that Brown 's behavior upset staff at his office , 10 Downing Street , so much so that the head of the civil service launched an investigation and `` ordered '' the prime minister `` to change his behavior . ''

Britain has a professional civil service which runs the administration of the government , distinct from elected politicians .

The Cabinet Office , a part of the civil service , issued a strongly-worded denial that Sir Gus O'Donnell had looked into Brown 's behavior or warned him about it .

`` It is categorically not the case that the Cabinet secretary asked for an investigation of the -LRB- prime minister 's -RRB- treatment of Number 10 staff , '' his office said in a statement . `` These assertions have been put to the Cabinet secretary who has rejected them . ''

Before the publication of the excerpts from the book , there were rumors it would allege that Brown had hit staffers , which he denied Saturday .

`` Let me just say , absolutely clearly , so that there is no misunderstanding about that : I have never , never hit anybody in my life , '' he said , according to a statement from his office .

The book , `` The End of the Party , '' apparently does not claim the prime minister hit people .

Brown is required by law to call an election by June this year . The date has not yet been announced , but it is widely expected to be May 6 , and the election campaign has already started .

One of the top strategists in Brown 's Labour Party , Peter Mandelson , declined to deny that Brown had a temper , but painted his personality as a virtue .

`` I do n't think he so much bullies people as he 's very demanding of people . He 's demanding of himself , he 's demanding of people around him , '' Mandelson said on the BBC 's `` Andrew Marr Show '' on Sunday .

`` He does not like taking no for an answer ... . there is a degree of impatience about the man , but what would you like ? Some sort of shrinking violet at the helm of the government ? '' Mandelson asked .

Mandelson laughed and dodged a question from Marr about whether Brown had ever hit him or shouted at him .

But he said Rawnsley had a history of writing about events he had not witnessed .

`` He 's a very good , colorful writer , but that 's it , '' Mandelson said .

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Brown accused of `` abusive behavior '' , `` volcanic eruptions of foul temper ''

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Journalist claims Brown 's behavior was investigated by a top civil servant

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Brown `` ordered to change his behavior , '' Andrew Rawnsley 's book claims

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Brown spokesman : `` Malicious allegations are totally without foundation ''